Where can I measure 25 megahertz intended for HSE?

[MMust.5]

STM32F407 Discovery

en.MB997-F407VGT6-C01_Schematic.pdf

HSE quartz 8 megahertz.

How are 4-26 MHz generated for HSE?

With an oscilloscope, I see only 8 megahertz on X2 quartz.

Where are those 25 megahertz that are listed as input for HSE?

In the documentation I read this:

This frequency cannot be changed, it is fixed at 8 MHz and connected to PH0-OSC_IN of the STM32F407VG.

But in Cube Mx this frequency can be changed from 4 to 26 megahertz.

[AScha.3 · Accepted solution]

>Where are those 25 megahertz that are listed as input for HSE?

on a board with 25MHz crystal (i have one of these here)

> in Cube Mx this frequency can be changed from 4 to 26 megahertz

how should Cube know, what crystal you decide to use ???

>it is fixed at 8 MHz and connected to PH0-OSC_IN

exactly. until you solder another crystal there in. then set this new frequency in Cube!